1. Field of the Invention
The present invention relates to an AV system, an amplifier, and a content reproducing device, and more particularly, to an AV system including an amplifier and a content reproducing device and connected to a display, and an amplifier and a content reproducing device in such an AV system.
2. Description of the Related Art
In recent years, AV systems including an amplifier such as an AV receiver and a content reproducing device such as a DVD reproducing device have come into wide use. As shown in FIG. 15, an AV receiver 100 in such an AV system 700 receives a DVD video signal DVS and an audio sound signal AS from a DVD reproducing device 300 connected to the AV receiver 100 and relays the DVD video signal DVS to a display 200. After prescribed signal processing is carried out to the received audio sound signal AS, the resulting signal is transmitted to the speaker 400. In this way, the user can enjoy high quality sounds resulting from processing by the AV receiver 100 while reproducing high picture quality video using the DVD reproducing device 300.
Another type of connection possible between the AV system 700 and the display 200 is the type of connection shown in FIG. 16. In this case, a DVD video signal DVS output from the DVD reproducing device 300 is directly input to the display 200. Therefore, the transmission path for the DVD video signal DVS is shorter than that of the connection in FIG. 15, and better picture quality can be provided.
The AV receiver 100 has an OSD (On Screen Display) function. By the OSD function, a screen for settings (hereinafter as “OSD screen”) for the AV receiver 100 is displayed at the display 200. In this way, the user can adjust the settings for the AV receiver such as adjusting audio sounds while looking at the OSD screen. When the OSD screen is displayed, the AV receiver 100 outputs an OSD signal to the display 200.
Note however that in the connection in FIG. 16, the display 200 cannot display the OSD screen of the AV receiver 100. This is because the DVD reproducing device 300 cannot transmit the OSD signal output from the AV receiver 100 to the display 200 while outputting a DVD video signal DVS. Therefore, the user cannot adjust settings such as audio sounds for the AV receiver 100 while looking at the OSD screen while a DVD is reproduced. It is preferable that the user can carry out adjustment for synchronization while looking at the video and the OSD screen at the same time particularly when the video based on the DVD video signal DVS and audio sounds based on the audio sound signal AS are synchronized.
The same disadvantage is encountered in the type of connection in FIG. 15. When the DVD reproducing device 300 outputs the DVD video signal DVS, the AV receiver 100 can output the input DVD video signal DVS and an OSD signal it produces to the display 200 at the same time. However, when the DVD reproducing device 300 outputs a digital DVD video signal DVS such as an HDMI (High-Definition Multimedia Interface) signal and a DVI (Digital Visual Interface) signal, the AV receiver 100 cannot simultaneously transmit the digital DVD video signal DVS and the OSD signal it produces to the display 200. The AV receiver 100 cannot output a digitally input signal and another signal at the same time to the display 200, in other words, it can output only the digital signal.